The present invention relates to magnetic recording and/or reproducing apparatuses such as, for example, video tape recorders (VTR), digital audio tape recorders (R-DAT) or the like, for use with tape cassettes each having accommodated therein a magnetic tape.
In a general magnetic recording and/or reproducing apparatus for use with a tape cassette having accommodated therein a magnetic tape, a portion of the magnetic tape is drawn out of the tape cassette and is wrapped about a head drum or rotary head. The magnetic tape is run in wrapping relation to the head 15 drum so that signals are recorded on or reproduced from the magnetic tape.
The magnetic recording and/or reproducing apparatus comprises a tape cassette loading mechanism for moving the tape cassette between a tape cassette unloading position where the tape cassette can be unloaded from the apparatus and a tape cassette loading position where the tape cassette is located at a predetermined position with respect to the head drum. The apparatus further comprises a tape loading mechanism which has a pair of tape loading posts movable between their respective tape unloading positions where the tape loading posts are located on the inside of the magnetic tape portion extending within the tape cassette and respective tape loading positions where the tape loading posts are located remote from the tape cassette to wrap the magnetic tape portion about the head drum. Component parts such as a pinch roller and the like are moved in synchronism with movement of the tape loading posts between the tape loading and unloading positions.
Conventional magnetic recording and/or reproducing apparatuses of the kind referred to above are disclosed, for example, in Japanese Patent Application Laid-Open Nos. 61-204855 and 61-202362.
The apparatus disclosed in Japanese Patent Application Laid-Open No. 61-204855 will be described with reference to FIGS. 1 and 2 of the accompanying drawings. The apparatus comprises a tape cassette holder 1 and a pair of rack plates 2 (only one shown in FIG. 1) which are fixedly mounted respectively to the opposite sides of the tape cassette holder 1. Each of a pair of side wall plates 4 (only one shown in FIG. 1) fixedly secured to a chassis 3 is arranged on the outside of a corresponding one of the rack plates 2. Each of the side wall plates 4 is formed therein with three guide slots 5a, 5b and 5c. Three follower pins 6a, 6b and 6c are attached to each of the rack plate 2 and are slidably fitted respectively in the three guide slots 5a, 5b and 5c. Each of the rack plates 2 is provided therein with an opening 7, and rack gear teeth 8 are formed along a side edge of the opening 7. In mesh with the rack gear teeth 8 is a pinion 9 which is adapted to be driven for rotation by a tape cassette loading motor (not shown).
In the illustrated apparatus, a tape cassette 10 is mounted on the tape cassette holder 1 as indicated by the dot-and-dash lines in FIG. 1. When the tape cassette 10 is mounted on the tape cassette holder 1 as shown in FIG. 1, the tape cassette loading motor is driven to rotate the pinion 9 thereby moving the rack plates 2 and the tape cassette holder 1 from a position indicated by the dot-and-dash lines to a position indicated by the solid and broken lines, along the configuration of the guide slots 5a, 5b and 5c. When the tape cassette holder 1 is moved to the position indicated by the solid and broken lines, the tape cassette 10 is located at its tape cassette loading position within the apparatus, as shown in FIG. 2. As the tape cassette 10 is located at the tape cassette loading position, a tape loading motor (not shown) is driven to move a pair of tape loading posts 12 (only one shown in FIG. 2) to the left as viewed in FIG. 2 thereby drawing a portion 11 of a magnetic tape out of the tape cassette 10. The drawn magnetic tape portion 11 is wrapped about a head drum (not shown). The magnetic tape portion 11 is run in wrapping relation to the head drum so that signals are recorded on or reproduced from the magnetic tape.
FIGS. 3 through 5 show the magnetic recording and/or reproducing apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 61-202362. The apparatus comprises a chassis 15 which is formed therein with an opening 16 and a pair of guide slots 17a and 17b. A supply reel mount 18a and a takeup reel mount 18b are arranged within the opening 16. A head drum 20 is mounted on the chassis 15 at a location between the guide slots 17a and 17b. A pair of movable blocks 21a and 21b are fitted respectively in the guide slots 17a and 17b for sliding movement therealong. A pair of tape loading posts 22a and 22b are fixedly mounted respectively to the movable blocks 21a and 21b.
As best shown in FIG. 5, a pair of loading rings 23 and 24 are rotatably arranged on the side of a lower surface of the chassis 15 in surrounding relation to the head drum 20. These loading rings 23 and 24 are drivingly connected to a loading motor 25 through a gear train 26 such that the loading rings 23 and 24 are angularly moved by the motor 25 in their respective directions opposite to each other.
The loading ring 23 is connected to the movable block 21b through a connecting arm 27a, while the loading ring 24 are connected to the movable block 21a through a connecting arm 27b. The loading ring 23 has mounted thereto a pinch roller arm pusher 28 on which a guide post pusher 29 is supported.
A pinch roller arm 31 is pivotally mounted on a pivot 30 fixed to the chassis 15. The pinch roller arm 31 has a free end thereof on which a pinch roller 32 is rotatably mounted through a support shaft 33. When the pinch roller arm 31 angularly moves about the pivot 30, the pinch roller 32 moves toward and away from a capstan 34. A support arm 36 is pivotally mounted on a pivot 35 fixed to the chassis 15. The support arm has a free end thereof on which a movable guide post 37 is mounted.
A tape cassette 38 having accommodated therein a magnetic tape 39 is adapted to be loaded in the apparatus at a position indicated by the two-dot-and-dash lines in FIGS. 3 and 4. FIG. 3 shows a tape unloading position before a portion of the magnetic tape 39 is drawn out of the tape cassette 38. In this tape unloading position, the tape loading posts 22a and 22b, the pinch roller 32 and the movable guide post 37 are located on the inside of the magnetic tape portion extending along the front edge of the tape cassette 38. As the loading motor 25 is driven for rotation, the loading ring 23 is angularly moved in the counterclockwise direction as viewed in FIG. 3, while the loading ring 24 is angularly moved in the clockwise direction. By such angular movements of the respective loading rings 23 and 24, the movable blocks 21a and 21b as well as the tape loading posts 22a and 22b are moved along the respective guide slots 17a and 17b rearwardly, i.e., upwardly as viewed in FIG. 3. As the loading ring 23 is angularly moved through a predetermined angle, the pusher 28 is abutted against the support shaft 33 and the pusher 29 is abutted against the movable guide post 37, to thereby cause the pinch roller 32 and the movable guide post 37 to angularly move respectively the pinch roller arm 31 and the support arm 36 in the clockwise direction about their respective pivots 30 and 35. As the tape loading posts 22a and 22b, the pinch roller 32 and the movable guide post 37 are moved rearwardly, the magnetic tape portion is drawn by these component parts out of the tape cassette 38, and the drawn magnetic tape portion is wrapped about the head drum 20. At this time, the pinch roller 32 urges the magnetic tape portion against the capstan 34. FIG. 4 shows a state in which the magnetic tape portion is moved to the tape loading position. In this state, if a play command is given, the capstan 34 and the head drum 20 are rotated to enable signals to be recorded on or reproduced from the magnetic tape 39.
In the apparatus described above with reference to FIGS. 3 through 5, the tape drive arrangement is such that the pair of loading rings 23 and 24 are employed to drive the tape loading posts 22a and 22b, the pinch roller 32 and the movable guide post 37. Accordingly, in the tape drive arrangement, the pair of loading rings 23 and 24 cannot but be arranged so as to surround the head drum 20. Thus, the tape drive arrangement cannot be said rational from the space point of view, and it is difficult for such tape drive arrangement to simplify the construction of the apparatus, to reduce the weight of the apparatus, and to reduce the overall size or dimension of the apparatus.
In order to dissolve the above-described problems of the apparatus disclosed in Japanese Patent Application Laid-Open No. 61-202362, a tape drive arrangement shown in FIG. 6 has been proposed in Japanese Patent Application Laid-Open No. 58-147836.
FIG. 6 is a bottom view of a magnetic recording and/or reproducing apparatus which comprises a base plate 40 and a head drum 41 mounted on the base plate 40.
The base plate 40 is formed therein with a pair of guide slots 42 and 43 on either side of the head drum 41. Fitted respectively in the guide slots 42 and 43 are a pair of tape drawing members 46 and 47 on which a pair of tape loading posts 44 and 45 are mounted respectively. A pair of drive gears 48 and 49 in mesh with each other are mounted on a lower surface of the base plate 40 through respective support shafts 50 and 51. The drive gears 48 and 49 are provided with their respective projections 52 and 53. A small-diameter gear 54 is mounted to the drive gear 49 for rotation therewith about a common axis. The projection 52 is connected to the tape drawing member 46 through a link 55, while the projection 53 is connected to the tape drawing member 47 through a link 56. In addition, a geared arm 58 formed with gear teeth 58A is mounted to the lower surface of the base plate 40 through a pivot 57 such that the gear teeth 58A on the geared arm 58 are in mesh with the gear 54.
A pinch roller 60 is provided which is movable toward and away from a capstan 59.
Rotational force of a loading motor 62 is transmitted to the geared arm 58 through a rotary member 63, a cam 64 and a sector gear 65. Driving force of the cam 64 is transmitted to the pinch roller 60 through a rod 66 and a linkage 67.
FIG. 6 shows an unloading state before a portion of a magnetic tape (not shown) is drawn out of a tape cassette (not shown). In this unloading state, the tape loading posts 44 and 45 are located on the inside of the magnetic tape portion extending within the tape cassette. As the loading motor 62 is driven for rotation, the geared arm 58 is angularly moved about the support shaft 57 in the clockwise direction indicated by the arrow in FIG. 6 so that the drive gear 49 is angularly moved in the counterclockwise direction and the drive gear 48 is angularly moved in the clockwise direction. By such angular movements of the respective drive gears 48 and 49, their respective projections 52 and 53 cause the respective tape drawing members 46 and 47 to be moved rearwardly. The tape loading posts 44 and 45 draw the magnetic tape portion out of the tape cassette to wrap the magnetic tape portion about the head drum 41. The pinch roller 60 urges the drawn magnetic tape portion against the capstan 59. Thus, signals can be recorded on or reproduced from the magnetic tape.
According to the tape drive arrangement described above with reference to FIG. 6, component parts for driving the tape loading posts 44 and 45 can be collected together on one side of the head drum 41, making it possible to achieve simplification of the construction of the apparatus, and reduction in weight and size or dimension of the apparatus.
In the tape drive arrangement illustrated in FIG. 6, there are a state or stop mode in which the tape loading posts 44 and 45 are moved to their respective tape loading positions, but the pinch roller 60 is not yet urged against the capstan 59, and a state or play mode in which the pinch roller 60 is moved from the stop mode position to a position where the pinch roller 60 is urged against the capstan 59. In the tape drive arrangement illustrated in FIG. 6, it may be considered to drive the pinch roller 60 by the drive mechanism for the tape loading posts 44 and 45 when switching is effected between the play mode and the stop mode. If it is possible to drive the pinch roller 60 by the drive mechanism for the tape loading posts 44 and 45, the apparatus would be simplified in construction. However, it is impossible for the arrangement of the apparatus illustrated in FIG. 6 to drive the pinch roller 60 directly by the drive mechanism for the tape loading posts 44 and 45, which comprises the drive gears 48 and 49, the gear 54, the geared arm 58 and the sector gear 65.
That is to say, in the apparatus illustrated in FIG. 6, the geared arm 58 for angularly moving the drive gears 48 and 49 cannot but be so arranged as to project from the gear 54 away from the head drum 41. For such arrangement, the geared arm 58 can only be swung to the right and left so that the angularly moving extent of the geared arm 58 is extremely limited. In addition, since the drive gears 48 and 49 are also in mesh with the geared arm 58, the angularly moving extents of the respective drive gears 48 and 49 are limited. Moreover, since these drive gears 48 and 49 are provided respectively with the projections 52 and 53, the drive gears 48 and 49 cannot be angularly moved in excess of 180 degrees. In this manner, in the arrangement illustrated in FIG. 6, the angularly moving extents of the respective drive gears 48 and 49 and geared arm 58 are limited, and it is impossible to further angularly move the drive gears 48 and 49 and the geared arm 58 after the tape loading posts 44 and 45 are moved to their respective tape loading positions. Thus, it is impossible for the arrangement to drive the pinch roller 60 by the drive mechanism for the tape loading posts 44 and 45.
Furthermore, each of the apparatus illustrated in FIGS. 1 and 2 and the apparatus illustrated in FIGS. 3 through 5 is so arranged as to comprise a tape cassette loading motor for loading the tape cassette, and a separate, tape loading motor for loading the magnetic tape. That is, each of the apparatuses necessitates provision of two separate loading motors. This raises the cost of the apparatuses. In addition, the space factor is low so that an attempt cannot be made to reduce the overall size or dimension of the apparatuses.
Moreover, as described above with reference to FIG. 1, the conventional tape cassette loading mechanism includes three guide slots in each of the opposite side wall plates. This increases the height dimension of the tape cassette loading mechanism, making it difficult to achieve reduction in overall dimension of the apparatus. That is, it is difficult to make the apparatus compact in construction. In addition, assembling operation is troublesome, because the three follower pins projecting from each side of the tape cassette holder are required to be fitted simultaneously into the respective guide slots in the corresponding side wall plate.